High solids emulsions of silylated elastomeric polymers

ABSTRACT

Water-continuous emulsion of silylated elastomeric polymers are disclosed having a solids content of greater than 75%, an average particle size less than 5 μm, and having sufficient stability to produce a stable lower solids emulsion upon dilution with water comprising; a silylated elastomeric polymer, surfactant, water, optional plasticizer, and optional low molecular weight acid.  
     The water-continuous emulsions of silylated elastomeric polymers can be prepared by; (I) forming a premix comprising an elastomeric polymer and surfactant, and optionally a plasticizer and low molecular weight acid, and (II) adding water to the premix with mixing to form a water continuous emulsion of the silylated elastomeric polymer having a solids content of greater than 75%, an average particle size less than 5 μm, and having sufficient stability to produce a stable lower solids emulsion upon dilution with water.

CROSS-REFERENCE

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/905,659 filed Jul. 13, 2001 currently pending.

FIELD OF THE INVENTION

[0002] This invention relates to water-continuous emulsions of silylatedelastomeric polymers and processes for preparing such emulsions. Inparticular, this invention relates to high solids water-continuousemulsions of silylated elastomeric polymers having a solids contentgreater than 75%, an average particle size less than 5 μm.

BACKGROUND OF THE INVENTION

[0003] Emulsions of high molecular weight polymers are commonly preparedusing emulsion polymerization or suspension polymerization techniques.These techniques involve first preparing emulsions or suspensions of themonomer starting materials, and subsequently polymerizing the monomersin-situ to create the high molecular weight polymers. Such techniquesavoid the handling and processing problems associated with highmolecular weight polymers. However, the type of high molecular weightpolymers that can be prepared by such techniques are often limited, andfurthermore, the resulting physical properties of the emulsions canoften limit their use in many applications.

[0004] Alternatively, emulsions of high molecular weight polymers havebeen prepared by first dispersing the preformed high molecular weightpolymer in a solvent. Some representative examples of this art are shownand others further discussed in U.S. Pat. Nos. 4,177,177 and 6,103,786.Also representative of this art are techniques known to create latexemulsions, illustrative examples of this art are taught in U.S. Pat.Nos. 3,360,599, 3,503,917, 4,070,325, 4,243,566, 5,554,726, 5,574,091and 5,798,410, where the high molecular weight polymer is dispersed in asolvent and is subsequently emulsified.

[0005] High internal phase emulsions of high molecular weight polymersare described in U.S. Pat. Nos. 5,539,021, 5,688,842, and 6,156,806.However, these examples also require the use of organic solvents todissolve the high molecular polymers.

[0006] The presence of solvent in emulsions can be hazardous in certainapplications or limit usage in other instances because of environmentalconcerns. For example, many of the commercially important volatileorganic solvents are also hazardous to health and environment such asozone depletion, air pollution, and water contamination. The presence ofsuch volatile solvents in emulsions are highly undesirable to both theproducers and the users of emulsions as special handling precautions andequipments are required to minimize the workers' exposure and release toenvironment.

[0007] Alternative techniques have thus been sought to prepare emulsionsof preformed high molecular weight polymers that avoid the shortcomingsmentioned above. For example, U.S. Pat. No. 4,123,403 provides acontinuous process for preparing aqueous polymer microsuspensions.Aqueous microsuspensions of solid polymers are prepared by a continuousprocess comprising the steps of (a) forming a heterogeneous compositionhaving a discontinuous aqueous phase and a continuous polymer phase attemperatures above the polymer melting point (e.g. melting above 20°C.), and (b) converting the resulting polymer continuous heterogeneouscomposition to a water-continuous heterogeneous composition. The '403patent describes its process as useful for solid polymers, and forthermoplastic solids whose degradation point is somewhat higher than itsmelting point, and is particularly useful for polymers having a meltflow rate of less than about 40, and temperature sensitive polymers.

[0008] Emulsions of high molecular weight polyisobutylene have beenreported in Japanese Patent Application Publications 58208341, 59122534,7173346, 10204234, and 10204235. The publications describepolyisobutylene emulsions having a 1-75% solid content which areprepared with specific types of surfactants, for example a combinationof polyoxyethylene-oxypropylene block polymer with polyoxyethylene alkylether sulfate ester are described in JP 10204234.

[0009] Emulsions of pre-formed high molecular weight silicones have beenreported. For example, U.S. Pat. Nos. 5,806,975 and 5,942,574 describe amethod for continuous emulsification of organopolysiloxane gumsinvolving a compounding extruder of a specific design, which requires aminimum shear rate of 10 sec−1. While the '975 and '574 patents describeits apparatus and method as capable of emulsifying organopolysiloxanegums having a viscosity in excess of 500,000 centipoise, examples werelimited to a trimethylsiloxy-endblocked dimethylpolysiloxane gum with aviscosity of 10 million centipoises (10 KPa-s).

[0010] U.S. Pat. No. 5,840,800 describes crosslinked emulsions ofpre-formed silicon modified organic polymers having a viscosity of 5-500Pa-s and a glass transition temperature of less than 20° C. The '800process describes the formation of a crosslinked emulsion by a) formingan emulsion of silicon modified organic polymers having a viscosity of5-500 Pa-s (or 0.005-0.5 KPa-s) and b) allowing crosslinking to occurwithin the emulsion resulting in emulsions of crosslinked polymers.

[0011] Processes are needed for the preparation of high solids emulsionsof preformed high viscosity elastomeric polymers and elastomericpolymers with curable functionalities. Furthermore, high solidsemulsions of elastomeric polymers that are stable with time, and can befurther diluted to produce stable emulsions are sought in manyindustrial processes such as coating applications. A high solidsemulsions (e.g. 75% by weight) of such elastomeric polymers will allowdevelopment of higher solids, water-based coatings, adhesives, andsealants formulations. The preparation of a high solids emulsion of highviscosity elastomeric polymers with curable functionalities will allowdevelopment of curable or crosslinkable coatings, adhesives, andsealants formulations with improved properties, performance andstability over their non-curable or pre-crosslinked elastomeric polymeranalogues.

[0012] Heretofore a method has not been disclosed for the preparation ofstable water-continuous emulsions of high viscosity silylatedelastomeric polymers having a high solids content, which also yieldsstable lower solids emulsions upon dilution.

[0013] An object of this invention is to provide a process for preparingwater continuous emulsions of silylated elastomeric polymers.

[0014] It is a further object of this invention to provide watercontinuous emulsions of silylated elastomeric polymers with a solidscontent greater than 75% by weight having a particle size of less than 5μm that are stable with time.

[0015] It is yet a further object of this invention to provide stableemulsions of silylated elastomeric polymers prepared by the dilution ofthe high solids emulsions of the silylated elastomeric polymer.

SUMMARY OF THE INVENTION

[0016] This invention relates to a water-continuous emulsion ofsilylated elastomeric polymers having a solids content of greater than75%, an average particle size less than 5 μm, and having sufficientstability to produce a stable lower solids emulsion upon dilution withwater comprising; a silylated elastomeric polymer, surfactant, water, anoptional plasticizer, and an optional low molecular weight acid.

[0017] This invention also relates to processes for preparingwater-continuous emulsions of silylated elastomeric polymers by; mixinga silylated elastomeric polymer, surfactant, and optionally aplasticizer and a low molecular weight acid, with water to form a watercontinuous emulsion of the silylated elastomeric polymer having a solidscontent of greater than 75%, an average particle size less than 5 μm,and having sufficient stability to produce a stable lower solidsemulsion upon dilution with water. In a preferred embodiment, the watercontinuous emulsions of silylated elastomeric polymers can be preparedby mixing a silylated elastomeric polymer, surfactant, optionalplasticizer, and optional low molecular weight acid with incrementalportions of water, whereby each incremental portion comprises less than8 weight % of the premix and each incremental portion of water is addedsuccessively to the previous after the dispersion of the previousincremental portion of water, wherein sufficient incremental portions ofwater are added to form the water-continuous emulsion of the silylatedelastomeric polymer. The present inventors have unexpectedly found thisstepwise addition of water in small incremental portions allows for theformation of the emulsion and enhances the emulsion stability atrelatively high solids contents.

DETAILED DESCRIPTION OF THE INVENTION

[0018] This invention relates to a water-continuous emulsion compositioncomprising;

[0019] (A) 100 parts of a silylated elastomeric polymer having aviscosity of 0.5-1,000,000 KPa-s and a glass transition temperature upto 50° C.,

[0020] (B) 3 to 30 parts surfactant

[0021] (C) 5 to 45 parts water

[0022] wherein the water-continuous emulsion has a solids content ofgreater than 75%, an average particle size less than 5 μm, havingsufficient stability to produce a stable lower solids emulsion upondilution with water.

[0023] As used herein, “water-continuous emulsion” refers to an emulsionhaving water as the continuous phase of the emulsion. Water-continuousemulsions are characterized by their miscibility with water and/or theirability to be diluted by the further addition of water.

[0024] As used herein, “silylated elastomeric polymer” refers to anyelastomeric polymer that has been modified to have at least one siliconatom attached to the polymer via a silane, organosilane, organosilylgroups or a siloxane segment of various chain lengths. Thesilicon-containing units may be reactive or non-reactive and may beattached at the terminal and/or pendant positions on the polymer chain.

[0025] The elastomeric polymers that can be used as starting materialsto prepare the silylated elastomeric polymers of the present inventionare any polymers having a viscosity of 0.5-1,000,000 KPa-s and a glasstransition temperature up to 50° C. One skilled in the art recognizesthe term elastomeric to describe materials as having rubber-likeproperties or rubbery characteristics, that is, materials which can beextended to twice its own length at room temperature or having anelongation of 100% or higher at room temperature. When the term“polymer” is used herein, it should be understood to describe polymersthat may be homopolymers, copolymers, terpolymers, and mixtures thereof.

[0026] For the purpose of this invention, the viscosity of the silylatedelastomeric polymer is defined as “zero-shear” viscosity at ambienttemperature. This is commonly defined as the viscosity of a polymer whenapproaching zero shear rate conditions and is regarded as a constantvalue for a given polymer. The “zero-shear” viscosity is an approximatedconstant viscosity value derived empirically or from experimentallymeasured viscosity values.

[0027] The silylated elastomeric polymers that can be emulsified by theprocess of the present invention can have a viscosity of 0.5 to1,000,000 KPa-s, preferably the viscosity is 0.5 to 500,000 KPa-s, andmost preferable is when the silylated elastomeric polymer has aviscosity of 1.0 to 100,000 KPa-s. While the correlation of viscosityand molecular weight will vary depending on the specific type ofpolymer, generally the number average molecular weights (Mn) of thesilylated elastomeric polymers that can be typically used in the presentinvention range from 5,000 to 300,000 g/mole, preferably 5,000 to200,000 g/mole, and most preferably range from 5,000 to 100,000 g/mole.

[0028] For purposes of this invention, the term “glass transitiontemperature” is the accepted meaning in the art, that is, thetemperature at which a polymer changes from a brittle vitreous state toa plastic state. The glass transition temperature can be determined byconventional methods such as dynamic mechanical analyzer (DMA) anddifferential scanning calorimetry (DSC). The silylated elastomericpolymers of the present invention should have a glass transitiontemperature of less than 50° C. Preferably, the silylated elastomericpolymers of the present invention should have a glass transitiontemperature of less than 30° C., and more preferably, the silylatedelastomeric polymers should have a glass transition temperature of lessthan 0° C.

[0029] The elastomeric polymers that can be used as starting materialsto prepare the silylated elastomeric polymers which can be emulsified bythe process of the present invention include, but are not limited to,the elastomeric polymers typically associated with the following generalclasses of elastomeric materials such as; natural rubber,styrene-butadiene, butadiene, ethylene-propylene-diene polymers (EPDM),butyl rubber, nitrile rubber, chloroprene rubber, fluorocarbonelastomers, polysulfide rubbers, and polyurethane.

[0030] The elastomeric polymers, which can be silylated and thensubsequently emulsified according to the present invention, can befurther defined to encompass those materials that exhibit the ability tobe extended to twice its own length at room temperature on its own,(hereafter referred to as “conventional elastomeric polymers”), or thosematerials that exhibit elastomer properties upon curing or crosslinking(hereafter referred to as “curable elastomeric polymers).

[0031] Illustrative examples of conventional elastomeric polymers whichcan be silylated and then subsequently emulsified according to thepresent invention include, but are not limited to: poly(olefins) andpoly(olefins-dienes) copolymers, and their derivatives, that is,polymers and copolymers derived from olefinic monomers C₂ to C₁₂, dienesC₄ to C₁₂ such as, polyethylene, polypropylene, poly(butene-1),poly(propylethylene), poly(decylethylene), poly(dodecylethylene),poly(butylethylene), poly(ethylethylene), poly(ethyl-2-propylene),poly(isopropylethylene), poly(isobutylethylene),poly(isopentylethylene), poly(heptylethylene), poly(tert-butylethylene),poly(ethyele-co-propylene), poly(ethylene-propylene-diene) terpolymers(EPDM); polymers and copolymers of monoolefin, isomonoolefin and vinylaromatic monomers, such as C₂ to C₁₂ monoolefins, C₄ to C₁₂isomonoolefins, vinyl aromatic monomers including styrene,para-alkylstyrene, para-methylstyrene, (methods of preparing suchpolymers can be found in U.S. Pat. No. 5,162,445, and U.S. Pat. No.5,543,484); poly(dienes) and derivatives; such as, polybutadiene,polyisoprene, poly(alkyl-butenylene) where alkyl can be a hydrocarbongroup containing 1 to 12 carbon atoms, poly(phenyl-butenylene),polypentenylene, natural rubber (a form of polyisoprene), butyl rubber(copolymer of isobutylene and isoprene), illustrative commercialexamples of polyisobutylenes suitable in the present invention areOppanol B products from BASF (BASF, Ludwigshafen, Germany), Vistanex™products from Exxon (Houston, Tex.), and Epion A products from Kaneka(Kanegafuchi Chemical Industry Co. Ltd. Tokyo, Japan and Kaneka AmericaCorp, New York, N.Y.); halogenated olefin polymers; such as from thebromination of copolymers of isomonoolefin with para-methylstyrene tointroduce benzylic halogen (as described in U.S. Pat. No. 5,162,445),halogenated polybutadienes, halogenated polyisobutylene such as Exxpro™products from Exxon-Mobil (Houston, Tex.), poly(2-chloro-1,3-butadiene),polychloroprene (85% trans), poly(1-chloro-1-butenylene) (Neoprene™),chlorosulfonated polyethylene; polyurethanes and polyureas; such aselastomeric polyurethanes and polyureas prepared from a wide variety ofmonomeric diisocyanates (aliphatic diisocyanates such as hexamethylenediisocyanate, cyclohexyldiisocyanate; aromatic diisocyanates such astoluene diisocyanate (TDI), bis(methylene-p-phenyl diisocyanate (MDI),isophorone diisocyanate (IPDI)), chain-extending diols, diamines, andoligomeric diols selected from polyether, polyester, polycarbonate, andpolycaprolatom; poly(alkyl acrylates), and poly (alkyl methacryaltes),that is polymers and copolymers derived from alkyl acrylates and alkylmethacrylates such as poly(methyl acrylate), poly(ethyl acrylate),poly(butyl acrylate), poly(isobutyl acrylate), poly(2-ethylbutylacrylate), poly(2-ethylhexyl acrylate), poly(n-octyl methacrylate),poly(dodecyl acrylate); copolymers and terpolymers of dienes, alkenes,styrenes, acrylonitriles, such as poly(butadiene-co-styrene),poly(butadiene-co-acrylonitrile), poly(butadiene-co-methyl metharyalte);poly(fluoroalkyl acrylates) that is polymers and copolymers derived fromfluoro-containing acrylates and methacrylates such aspolymer(fluoromethyl acrylate), poly(2,2,2-trifuoroethyl acryalte),poly(1H,1H-pentfluoropropyl acryate), poly(1H,1H,5H-octafluoropentylacrylate); poly(vinyl ethers) and poly(vinyl thioethers) such as thosepolymers derived from butoxyethylene, sec-butoxyethylene,tert-butoxyethylene, alkyl vinyl ether, propoxyethylene, vinyl methylether (methoxyethylene), hexyloxyethylene, 2-ethylhexyloxy ethylene,butylthioethylene; poly(oxyalkylenes) such as poly(oxyethylene),poly(oxypropylene), poly(oxythylene-co-propylene); plasticizercompounded thermoplastics, that is thermoplastics having elastomericbehavior because of the addition of a plasticizers or other compatibleadditives, such as poly(vinyl chloride) compounded with dioctylphthalate, tricresyl phophate, dibutyl sebacate, or poly(propyleneadipate); fluoro elastomers and chloro-containing polymers derived frompoly(alkylenes), poly(dienes) such as, poly(dichloroethyelene),poly(chlorofluoroethylene).

[0032] The elastomeric polymer which can be silylated and thensubsequently emulsified according to the present invention can also beselected from curable elastomeric polymers, that is, the group ofpolymers exhibiting elastomeric behavior upon curing or crosslinking.Generally, curable elastomeric polymers are polymers having reactivegroups contained therein that are able to crosslink during the curingprocess to yield an elastomeric polymer. Numerous reactive groups orcrosslinking/cure mechanisms are well known in the art, and all arebelieved to be useful in the present invention, providing the resultingelastomeric polymer meets the glass transition temperature and viscositylimits described supra. Thus, the curable elastomeric polymers can becharacterized by those conventional elastomeric polymers to which atleast one reactive group or functional group is attached such as analkenyl, vinyl, allyl, hydroxyl, carboxyl, epoxy, vinyl ether, oralkoxy. The reactive-group or functional group may be attached at aterminal and/or pendant position on the polymer chain. These curableelastomeric polymers should maintain the structural integrity during theemulsification process and subsequently in the emulsion state. Uponwater-removal, for example as in a coating application, thereactive-group or functional group cures to form a cured elastomericpolymer or coating of the elastomeric polymer. The curing may take placeby merely drying off the water, or assisted by an external catalyst,heat, radiation, moisture, or in conjunction with an external curative.

[0033] The curable elastomeric polymers which can be silylated and thensubsequently emulsified according to the present invention can be analkenyl-functional elastomeric polymer where the alkenyl group isselected from a hydrocarbon group containing 2 to 12 carbons such asvinyl, allyl, propenyl, butenyl, hexenyl, etc. The elastomeric polymersbearing such alkenyl functional groups may be derived from most of theconventional elastomeric polymers, as described above, includingpoly(olefins) and poly(olefins-dienes) copolymers, and theirderivatives: polymers and copolymers derived from olefinic monomers C₂to C₁₂, dienes C₄ to C₁₂; polymers and copolymers of monoolefin,isomonoolefin and vinyl aromatic monomers: monoolefin C₂ to C₁₂,isomonoolefin C₄ to C₁₂, vinyl aromatic monomers including styrene,para-alkylstyrene, para-methylstyrene; examples include polymers derivedfrom ethylene, propylene, isobutylene, isoprene, para-methylstyrene.

[0034] The curable elastomeric polymers which can be silylated and thensubsequently emulsified according to the present invention can also bepoly(dienes) and derivatives. Most of polymers, copolymers derived fromdienes usually contain unsaturated ethylenic units on backbone orside-chains that are curable. Representative examples includepolybutadiene, polyisoprene, polybutenylene, poly(alkyl-butenylene)where alkyl being C₁ to C₁₂, poly(phenyl-butenylene), polypentenylene,natural rubber (a form of polyisoprene); butyl rubber (copolymer ofisobutylene and isoprene).

[0035] The curable elastomeric polymers which can be silylated and thensubsequently emulsified according to the present invention can also be ahalogenated olefin polymer. Representative examples of a halogenatedolefin polymer include those polymers resulting from the bromination ofa copolymer of isomonoolefin with para-methylstyrene to introducebenzylic halogen (as described in U.S. Pat. No. 5,162,445), halogenatedpolybutadienes, halogenated polyisobutylene,poly(2-chloro-1,3-butadiene), polychloroprene (85% trans),poly(1-chloro-1-butenylene) (Neoprene™), chlorosulfonated polyethylene.The brominated poly(isobutylene-co-para-methylstyrene) can be furthercured via zinc oxide upon influence of heat.

[0036] The curable elastomeric polymers which can be silylated and thensubsequently emulsified according to the present invention can also bepolymers containing vinyl ether-, acrylate-, methyacrylate-, andepoxy-functional groups. Also, the elastomeric polymers can be hydroxylterminal or hydroxy containing poly(oxyalkylenes) polymers, such aspoly(oxyethylene), poly(oxypropylene), or poly(oxythylene-co-propylene)polymers.

[0037] The silylated elastomeric polymer can be selected from reactivesilane group-containing elastomeric polymers, mixtures of reactivesilane group-containing elastomeric polymers, blends of reactive silanegroup-containing elastomeric polymers with conventional elastomericpolymers, mixtures or blends of conventional elastomeric polymers withreactive silane group containing silicone polymers. The reactive silanegroups may be attached at the terminal and/or pendant positions on thepolymer chain and the total number of these reactive silicone groups maybe varied to provide a cured elastomeric structure with desirableproperties. Representative silane-modified elastomeric polymers aresilyated polymers and copolymers derived from olefins, such as theisobutylene polymers disclosed in U.S. Pat. No. 4,904,732, which ishereby incorporated by reference, isomonoolefin, dienes, ethylene orpropylene oxides, vinyl aromatic monomers from C2 to C12 such as thesilane-grafted copolymers of isomonoolefin and vinyl aromatic monomer asdiscussed in U.S. Pat. Nos. 6,177,519 B1 and 5,426,167. Commericalproducts illustrative of silylated propylene oxide polymers are the MSPolymers from Kaneka (Kanegafuchi Chemical Industry Co. Ltd. Tokyo,Japan and Kaneka America Corp, New York, N.Y.). Other representativesilicon-modified elastomeric polymers are illustrated by, but notlimited to; alkenylsilyl-functional elastomeric polymers such asvinylsilyl-, allylsilyl-, hexenylsilyl-containing elastomeric polymersthat are curable to form and further the elastomeric polymer structure;and alkoxysilyl-functional elastomeric polymers such as polymerscontaining at least one alkoxylsilyl groups and/or their hydrolysatesselected from methoxysilyl, dimethoxysilyl, trimethoxysilyl,ethoxysilyl, diethoxysilyl, triethoxysilyl, and methoxyethoxylsilyl.

[0038] In a preferred embodiment of the present invention, the silylatedelastomeric polymer is selected from the silylated copolymers of anisomonoolefin and a vinyl aromatic monomer as described in U.S. Pat. No.6,177,519 B1, which is hereby incorporated by reference. The silylatedcopolymers may be characterized as the addition product of an olefincopolymer radical created by contact of the copolymer with a freeradical generating agent and an olefinically unsaturated, hydrolyzablesilane wherein the silane adds to the polymer backbone to produce asilane grafted or silane modified copolymer product.

[0039] Illustrative examples of olefin copolymers suitable formodification with silanes to produce the preferred silylated copolymersof the present invention comprise copolymers containing at least 50 mole% of at least one C₄ to C₇ isomonoolefin and from 0.1 up to 50 mole % ofat least one vinyl aromatic monomer. Preferred vinyl aromatic monomersare mono-vinyl aromatics such as styrene, alpha-methylstyrene,alkyl-substituted styrenes such as t-butylstyrene and para-alkylsubstituted styrenes wherein the alkyl group contains from 1 to 4 carbonatoms, more preferably para-methylstyrene. Suitable isomonoolefinmonomers include isobutylene and the like. Preferably, 100% of theisomonoolefinic content of the copolymer comprises isobutylene.Preferred olefin copolymers include elastomeric copolymers comprisingisobutylene and para-methylstyrene and containing from about 0.1 to 20mole % of para-methylstyrene. These copolymers have a substantiallyhomogeneous compositional distribution such that at least 95% by weightof the polymer has a para-methylstyrene content within 10% of theaverage para-methylstyrene content of the polymer. They are alsocharacterized by a narrow molecular weight distribution (Mw/Mn) of lessthan about 5, more preferably less than about 3.5, a glass transitiontemperature (T_(g)) of below about −50° C. and a number averagemolecular weight (Mn) in the range of about 2,000 to 1,000,000, and evenmore preferably from 10,000 to 50,000.

[0040] Suitable unsaturated organic silanes which can be reacted withthe olefin copolymer backbone to produce the preferred silylatedcopolymers of the present invention are of the general formula RR′SiY₂wherein R represents a monovalent olefinically unsaturated hydrocarbonor hydrocarbonoxy radical reactive with the free radical sites-producedon the backbone polymer, Y represents a hydrolyzable organic radical andR′ represents an alkyl or aryl radical or a Y radical. Where R is ahydrocarbonoxy radical, it should be non-hydrolyzable. In the preferredembodiment R may be a vinyl, allyl, butenyl, 4-pentenyl, 5-hexenyl,cyclohexenyl or cyclopentadienyl radical, with vinyl being the mostpreferred radical. The group Y may be one or a mixture of C₁ to C₄alkoxy radical such as methoxy, ethoxy or butoxy; Y may also be selectedfrom acyloxy radicals such as formyloxy, acetoxy or propionoxy; oximoradicals such as —ON═C(CH₃)₂, —-ON═C(CH₃)(C₂H₅) and —ON═C(C₆H₅)₂; orsubstituted amino radicals such as alkylamino or arylamino radicals,including —-NHCH₃,—-NHC₂H₅ and —-NHC₆H₅ radicals. The group R′represents either an alkyl group, an aryl group or a Y group. The groupR′ can be exemplified by a methyl, ethyl, propyl, butyl, phenyl,alkylphenyl group or a Y group. Preferably, R′ is a methyl or alkoxygroup. The most preferred silanes are those where R′ and Y are selectedfrom methyl and alkoxy groups, e.g., vinyltriethoxysilane,vinyltrimethoxysilane and methyl vinyl dimethoxysilane.

[0041] Preferably, the free radical initiator used to create thepreferred silylated copolymers of the present invention is an organicperoxide compound having a half-life, at the reaction temperature, ofless than one tenth of the reaction/residence time employed.

[0042] The term “surfactant” is meant to describe a surface active agentselected from cationic surfactants, anionic surfactants, amphotericsurfactants, nonionic surfactants, and mixtures thereof which stabilizesthe dispersed phase of the emulsion. Each of these types of surfactants,which are known in the art as being useful in stabilizing emulsions ofelastomeric polymers, whether individually or combined with another typeof surfactant, are also useful as a surfactant in the instant invention.

[0043] Suitable cationic surfactants include, but are not limited to,aliphatic fatty amines and their derivatives such as dodecylamineacetate, octadecylamine acetate and acetates of the amines of tallowfatty acids; homologues of aromatic amines having fatty chains such asdodecylanalin; fatty amides derived from aliphatic diamines such asundecylimidazoline; fatty amides derived from disubstituted amines suchas oleylaminodiethylamine; derivatives of ethylene diamine; quaternaryammonium compounds such as tallow trimethyl ammonium chloride,dioctadecyldimethyl ammonium chloride, didodecyldimethyl ammoniumchloride and dihexadecyldimethyl ammonium chloride; amide derivatives ofamino alcohols such as beta-hydroxyethylsteraryl amide; amine salts oflong chain fatty acids; quaternary ammonium bases derived from fattyamides of disubstituted diamines such as oleylbenzylamino-ethylenediethylamine hydrochloride; quaternary ammonium bases of thebenzimidazolines such as methylheptadecyl benzimidazole hydrobromide;basic compounds of pyridinium and its derivatives such ascetylpyridinium chloride; sulfonium compounds such as octadecylsulfoniummethyl sulfate; quaternary ammonium compounds of betaine such as betainecompounds of diethylamino acetic acid and octadecylchloro-methyl ether;urethanes of ethylene diamine such as the condensation products ofstearic acid and diethylene triamine; polyethylene diamines; andpolypropanolpolyethanol amines.

[0044] Suitable anionic surfactants include, but are not limited tosulfonic acids and their salt derivatives such as described in U.S. Pat.No. 3,294,725 to Findley et al., which patent is hereby incorporated byreference. These anionic surfactants can be exemplified by, but are notlimited to, alkali metal sulforicinates; sulfonated glycerol esters offatty acids such as sulfonated monoglycerides of coconut oil acids;salts of sulfonated monovalent alcohol esters such as sodiumoleylisethionate; amides of amino sulfonic acids such as the sodium saltof oleyl methyl tauride; sulfonated products of fatty acids nitrilessuch as palmitonitrile sulfonate; sulfonated aromatic hydrocarbons suchas sodium alphanaphthalene monosulfonate anddibutyldodecylbenzenesulfonate (DBSA); condensation products ofnaphthalene sulfonic acids with formaldehyde; sodium octahydroanthracenesulfonate; alkali metal alkyl sulfates, such as sodium lauryl sulfate;ether sulfates having alkyl groups of 8 or more carbon atoms,alkylarylsulfonates having 1 or more alkyl groups of 8 or more carbonatoms and dialkylsulfonates, each alkyl group having 8 or more carbonatoms, such as dioctyl sulfosuccinate.

[0045] Suitable amphoteric surfactants include, but are not limited to,lecithin, glycinates, betaines, sultaines and alkyl aminopropionates.These can be exemplified by cocoamphglycinate,coco-amphocarboxyglycinates, cocoamidopropylbetaine, lauryl betaine,cocoamido-propydroxy-sultaine, laurylsulataine, andcocoamphodipropionate.

[0046] Useful nonionic surfactants may be exemplified, but not limitedto, polyoxyalkylene :alkyl ethers, polyoxyalkylene sorbitan esters,polyoxyalkylene alkyl esters, polyoxyalkylene alkylphenyl ethers,ethoxylated amides, ethoxylated amines, ethoxylated siloxanes,polyvinylacetate hydrolysate, polyvinylalchohol, polyglycerols, andblock copolymers of propylene oxide and ethylene oxide and others. Whennonionic surfactants are used in the present invention, polyoxyalkylenealkyl ethers are preferred. Representative examples of commercialpolyoxyalkylene alkyl ethers, include Brij 30®, Brij 35L®, and Brij 97®produced by Uniqema (ICI Surfactants, Wilmington, Del.) and mixturesthereof.

[0047] The surfactant can also be selected from the reaction productsresulting from the reaction between a carboxylic acid functionalhydrocarbon group and an amine functional hydrocarbon. The carboxylicacid functional hydrocarbon can be any hydrocarbon having a carboxylicacid group present in the molecule. The carboxylic acid functionalhydrocarbon can be a linear or branched hydrocarbon, saturated orunsaturated, containing at least 4 carbon atoms in the molecule.Suitable carboxylic acid functional hydrocarbons include, but notlimited to; monoprotic acids of the general formula RCOOH, where Rrepresents a linear or branched hydrocarbon of containing 4 to 36 carbonatoms; ester containing monoprotic acids, such as adipic acid monoethylester, azelaic acid monomethyl ester; dimer acids, such as azelaci acid;trimer acids, such as the oligomeric product of unsaturated linearcarboxylic acid containing at least 12 carbons, for example Empol 1043(trimer acid of tall oil) or Empol 1045 (trimer acid of olelic acid)from Cognis Corporation (Cincinnati, Ohio). Preferably the carboxylicacid functional hydrocarbon is selected from the group of carboxylicacids commonly known as “fatty acids”, that is, carboxylic acids derivedfrom or contained in an animal or vegetable fat or oil. The fatty acidscan be either saturated or unsaturated. Representative examples of fattyacids include, but not limited to; lauric, palmitic, stearic, isostearicacid, tall oil, oleic, linoleic, and linolenic. Most preferably, thecarboxylic acid functional hydrocarbon is selected from fatty acids thatare liquid at room temperature.

[0048] The amine functional hydrocarbon can be any hydrocarboncontaining amine functionality within its molecule. Hydrophilic aminefunctional hydrocarbons are preferred, that is amine functionalhydrocarbons that have some miscibility with water. Suitable hydrophilicamine functional hydrocarbons include, but not limited to; primaryalcohol amines, such as ethanolamine; secondary amine alcohols such asdiethanolamine; tertiary amine alcohols, such as triethanol amine;polyamines with hydrophilic groups such as polyethylene oxide groups.Preferably the hydrophilic amine functional hydrocarbon is a secondaryamine alcohol, most preferably the hydrophilic amine functionalhydrocarbon is diethanolamine.

[0049] The carboxylic acid functional hydrocarbon and amine functionalhydrocarbon can be reacted together in any manner, but preferably theyare reacted together prior to mixing with the silylated elastomericpolymer. The temperature and pressure at which the reaction step occursis not critical, but generally is conducted at temperatures of 20 to120° C., preferably 40 to 80° C., and at atmospheric pressure. The molarratio of the carboxylic acid functional hydrocarbon to the aminefunctional hydrocarbon can vary, but typically is in the range of 3 to0.33, preferably 2 to 0.5, and most preferably 1.5 to 0.8.

[0050] Generally, the amount of surfactant used should be that amountwhich stabilizes the emulsion of the silylated elastomeric polymer. Anamount from 3 to 30 parts by weight based on 100 parts by weightsilylated elastomeric polymer should be sufficient. Preferably, thesurfactant is present in an amount from 5 to 15 parts by weight based on100 parts by weight silylated elastomeric polymer. More preferably, thesurfactant is present in an amount from 5 to 10 parts by weight based on100 parts by weight silylated elastomeric polymer.

[0051] The elastomeric polymer and surfactant can be mixed in thepresence or absence of solvents. If the mixture is formed in the absenceof solvents, it can be considered to be essentially free of organicsolvents. As used herein, the phrase “essentially free of organicsolvents” means that solvents are not added to the elastomeric polymerand surfactant premix in order to create a mixture of suitable viscositythat can be processed on typical emulsification devices. Morespecifically, “organic solvents” as used herein is meant to include anywater immiscible low molecular weight organic material added to thenon-aqueous phase of an emulsion for the purpose of enhancing theformation of the emulsion, and is subsequently removed after theformation of the emulsion, such as evaporation during a drying or filmformation step. Thus, the phrase “essentially free of organic solvent”is not meant to exclude the presence of solvent in minor quantities inprocess or emulsions of the present invention. For example, there may beinstances where the elastomeric polymer or surfactant used in thecomposition contains minor amounts of solvent as supplied commercially.Small amounts of solvent may also be present from residual cleaningoperations in an industrial process. Furthermore, small amounts ofsolvent may also be added to the process of the present invention forpurposes other than to enhance the formation of the water-continuousemulsion. Preferably, the amount of solvent present in the compositionshould be less than 5% by weight of the composition, more preferably theamount of solvent should be less than 2% by weight of the composition,and most preferably the amount of solvent should be less than 1% byweight of the composition.

[0052] Illustrative examples of “organic solvents” that are included inthe above definition are relatively low molecular weight hydrocarbonshaving normal boiling points below 200° C., such as alcohols, ketones,ethers, esters, aliphatics, alicyclics, or aromatic hydrocarbon, orhalogenated derivatives thereof.

[0053] As merely illustrative of solvents to be included in thedefinition of “organic solvents”, there may be mentioned butanol,pentanol, cyclopentanol, methyl isobutyl ketone, secondary butyl methylketone, diethyl ketone, ethyl isopropyl ketone, diisopropyl ketone,diethyl ether, secbutyl ether, petroleum ether, ligroin, propyl acetate,butyl and isobutyl acetate, amyl and isoamyl acetate, propyl andisopropyl propionate, ethyl butyrate, pentane, hexane, heptane,cyclopentane, cyclohexane, cycloheptane, methylene chloride, carbontetrachloride, hexyl chloride, chloroform, ethylene dichloride, benzene,toluene, xylene, chlorobenzene, and mixtures thereof with each otherand/or more water soluble solvents.

[0054] A plasticizer (D) may be added as an optional component to thecomposition. As used herein, “plasticizer” is meant to describe anyadditive to the composition added for the purpose of enhancing themixture of the surfactant with the elastomeric polymer. Generally, theplasticizer should be compatible and miscible with the elastomericpolymer and has one or more of the following effects on the elastomericpolymer: reduces the viscosity of polymer, renders the polymer flexibleand easier to process, lowers the softening temperature, or increasesthe melt-flow characteristics. Addition of plasticizer is usuallyintended to reduce the viscosity and rigidity, and enhance theprocessing of the polymer.

[0055] Generally, the plasticizer can be selected from saturated orunsaturated hydrocarbons containing at least 8 carbon atoms.Illustrative examples of plasticizers useful in the present inventioninclude, but are not limited to: alkanes, for example straight,branched, or cyclic aliphatic hydrocarbons having the formulaC_(n)H_(2n+2); alkenes and alkynes; for example, unsaturatedhydrocarbons having chain length of at least C8, aromatic hydrocarbons,including alkylaryl hydrocarbons: cycloparaffinic compounds andvarieties of aromatic- and naphthenic-containing compounds; halogenatedalkanes or halogenated aromatic hydrocarbons: such as chlorinated,brominated derivatives of alkanes, halogenated aromatic or alkylarylhydrocarbons, alkanes or aromatic hydrocarbons in which some of thehydrogens are replaced by halogens such as chlorine, or bromine atoms;esters of carboxylic acids and phosphoric acids: such as isodecylpelargonate, dibutyl phthalate, dioctyl phthalate, diisodecyl phthalate,diisooctyl adipate, diisodecyl adipate, butyl benzyl phthalate;phosphates and polyesters: such as low to moderate molecular weightesterification products from acids, anhydrides, diacids, phosphates suchas 2-ethylhexyl diphenyl phosphate, tricresyl phosphate, cresyl diphenylphosphate; low and moderate molecular-weight elastomeric polymers oroligomers, such as oligomeric materials or low to moderatemolecular-weight polymers of similar structure to the elastomericpolymers exhibit excellent miscibility and compatibility with theelastomeric polymers, for example, low molecular weight polyisobutylene,and polybutene as plasticizer for polyisobutylene orpoly(isobutylene-co-p-methylstyrene) elastomers; Polyglycols, Polyols,polyalkyl glycols, polyalkylene glycols, ethers, and glycolates: such asbutyl phthalyl butyl glycolate, methyl phthalyl ethyl glycolate;Sulfonamides and cyanamides: such as cyclohexyl-p-toluene-sulfonamide,N-ethyl-p-toluenesulfonamide, p-toluenesulfonamide: Hydrophilicplasticizers, such as polyvinyl alcohol, poly(vinyl acetate) andpartially hydrolyzed; Terpene hydrocarbons such as terpentine, pinene,dipentene, terpineol, pine oil.

[0056] Generally, the plasticizer is selected from compounds having achemical structure that is similar to the chemical structure of thesilylated elastomeric polymer to be emulsified. For example, saturatedhydrocarbons such as mineral oil, or low molecular weight isobutyleneswould be preferred plasticizers when the silylated elastomeric polymeris a polyisobutylene.

[0057] The amount of plasticizer added to the composition can vary, butgenerally ranges from 0.1 to 100 parts by weight to 100 parts of thesilylated elastomeric polymer, preferably 0.1 to 50, and most preferablyranges from 0.1 to 30 parts by weight to 100 parts of the silylatedelastomeric polymer.

[0058] A low molecular weight acid (E) can also be added to thecomposition as an optional component. The addition of the low molecularweight acid is preferable when a silylated copolymer of isomonoolefinand a vinyl aromatic monomer is used as the silylated elastomericpolymer to be emulsified, and in particular when the silylated groupcomprises an alkoxy group. Although not to be limited by any theory, thepresent inventors believe the low molecular weight acid helps tominimize hydrolysis of the alkoxy silane present on the copolymer duringthe emulsification process.

[0059] The water-continuous emulsions of the silylated elastomericpolymer can be characterized as having an average particle sizedistribution of less than 5 μm, with a solids content of greater than75%, and are able to produce stable water-continuous emulsions uponfurther dilution with water. Average particle size distribution is theaccepted meaning in the art, and can be determined for example using aMalvern Mastersizer unit. “Solids content” is also the accepted meaningin the art, that is the weight percent of all non-aqueous componentsadded to the emulsion. For purposes of this invention, “stablewater-continuous emulsion” means that the emulsion's average particlesize distribution does not change substantially within a given period oftime, for example the average particle size remains less than 5 μm andno significant formation of particles larger than 5 μm occurs within atime period of 4 months. Thus, mixing additional water to the highsolids content water-continuous phase emulsion forms a diluted emulsionhaving stability of at least 4 months. The water-continuous emulsions ofsilylated elastomeric polymers having a solids content greater than 75%can be diluted to water-continuous emulsions having a solids content aslow as 5%, preferably the solids content upon dilution is 5 to 75% andmost preferably from 30 to 75%.

[0060] Illustrative, non limiting examples of low molecular weight acidssuitable in the present invention are: inorganic acids such ashydrochloric acid, sulfuric acid, phosphoric acid, and the like; andalso organic acids such as carboxylic acid functional hydrocarbonscontaining 1 to 8 carbon atoms, for example, formic acid, acetic acid,propionic acid, maleic acid, fumaric acid, and the like. Preferably thelow molecular weight acid is acetic acid.

[0061] The amount of low molecular weight acid added can vary, butgenerally ranges from 0.01 to 10 parts by weight to 100 parts of thesilylated elastomeric polymer, preferably, 0.01 to 5, and mostpreferably ranges from 0.01 to 3 parts by weight to 100 parts of thesilylated elastomeric polymer.

[0062] The present invention also relates to a process for preparing awater-continuous emulsion of a silylated elastomeric polymer comprising:

[0063] (I) Mixing;

[0064] (A) 100 parts of a silylated elastomeric polymer having aviscosity of 0.5 to 1,000,000 KPa-s and a glass transition temperatureup to 50° C.,

[0065] (B) 3 to 30 parts of a surfactant,

[0066] (C) 5 to 45 parts water

[0067] to form a water-continuous emulsion of the silylated elastomericpolymer having a solids content of greater than 75%, an average particlesize less than 5 μm, and has sufficient stability to produce a stablelower solids emulsion upon dilution with water.

[0068] The silylated elastomeric polymer and surfactant are the same asdefined above. Optional components (D) and (E), as described above, canalso be added to this method step.

[0069] The order of mixing is not critical, providing that the mixing isperformed in such a manner to produce a water continuous emulsion of thesilylated elastomeric polymer having a solids content of greater than75%, an average particle size less than 5 μm, and has sufficientstability to produce a stable lower solids emulsion upon dilution withwater. In a first embodiment of the process, components (A) and (B) andoptionally components (D) and (E) are mixed together to form a premix towhich is added with further mixing the water component (C), hereinreferred to as the premix embodiment described supra. In a secondembodiment of the process, components (B) and (C), optionally (D) and(E) are simultaneously added to component (A). In either embodiment,preferably the water (C) is added in incremental portions, whereby eachincremental portion comprises less than 8 weight % of the components (A)and (B) combined and each incremental portion of water is addedsuccessively to the previous after the dispersion of the previousincremental portion of water, wherein sufficient incremental portions ofwater are added to form the water-continuous emulsion of the silylatedelastomeric polymer. The present inventors have unexpectedly found thisstepwise addition of water in small incremental portions allows for theformation of the emulsion and greatly enhances the emulsion stability atrelatively high solids contents. Each incremental addition of water isadded and dispersed. Before adding the next incremental portion ofwater, the previous incremental portion should have been dispersed,meaning that no visible water droplets were present in the mixture.Preferably, the successive incremental portion of water comprises lessthan 4 weight % of the components (A) and (B) combined, and mostpreferably comprises less than 2 weight % of the components (A) and (B)combined.

[0070] Although not to be limited by any theory, the present inventorsbelieve the total amount of water added in incremental portions,according to the preferred embodiment of the present invention,represents the amount of water necessary to cause a phase inversion froma non-aqueous continuous mixture to a water-continuous emulsion. Thispoint is evidenced by the physical changes of the mixture that accompanythis particular stage of the process. These physical changes include theemulsion's ability to be readily diluted in water, and also thecreamy/lustrous appearance of the water-continuous emulsion.

[0071] Mixing of the components (A), (B), (C), and optionally (D) and(E) can be accomplished by any method known in the art to effect mixingof high viscosity materials. Thus, mixing can occur either as a batch,semi-continuous, or continuous process whereby the mixing is provided bymeans known in the art to mix high viscosity materials, for example,batch mixing equipments with medium/low shear include change-can mixers,double-planetary mixers, conical-screw mixers, ribbon blenders,double-arm or sigma-blade mixers; batch equipments with high-shear andhigh-speed dispersers include those made by Charles Ross & Sons (NY),Hockmeyer Equipment Corp. (NJ); batch equipments with high shear actionsinclude Banbury-type (CW Brabender Instruments Inc., NJ) and Henscheltype (Henschel mixers America, Tex.). Illustrative examples ofcontinuous mixers/compounders include extruders single-screw,twin-screw, and multi-screw extruders, twin-screw corotating extruders,such as those manufactured by Krupp Werner & Pfleiderer Corp (Ramsey,N.J.), and Leistritz (NJ); twin-screw counter-rotating extruders,two-stage extruders, twin-rotor continuous mixers, dynamic or staticmixers or combinations of these equipments. Furthermore, one may be ableto mix silylated elastomeric polymers of relatively low viscosity insuch conventional emulsification equipments as rotor-stator, colloidmills, homogenizers, and sonolaters.

[0072] The temperature and pressure at which the mixing occurs is notcritical, but generally is conducted at ambient temperature andpressures. Typically, the temperature of the mixture will increaseduring the mixing process due to the mechanical energy associated withshearing such high viscosity materials. Thus, lower shear rates willcause less of a temperature increase. Preferably the temperature iscontrolled to be below 60° C. to minimize undesirable side reactions.

[0073] The temperature increase in the mixture will also depend on thetype of mixing equipment used, high shear mixing generally results inhigh temperature build up. Also, the longer durations of mixing timewill result in greater temperature increases. While the temperature ofthe operation is not necessarily critical for forming emulsions ofconventional silylated elastomeric polymers, in other instances it maybe desirable to control the temperature to be below 60° C. Therefore,the preferred mixing equipments are those batch equipments with mediumto low shear rate such as Double-planetary mixers, low intensity,low-shear rate change-can mixers, and batch mixers equipped with highviscosity mixing capability or blades; and the preferred continuousmixers include twin-screw extruders, co-rotating or counter-rotating,single, two- or multi-stage extruders where the mixing times arerelatively short. Illustrative of the batch mixers and conditions thatcan be used to accomplish the mixing in the process of the presentinvention include but are not limited to: Ross mixers with HV blades(Charles Ross & Sons, NJ), a low speed, high power mixing deviceoperating at a very low shear rate of 1 sec−1 to 7 sec−1 (10 rpm-70rpm); Ross Powermix, a mixing and compounding device having two mixingblades, one scraper blade operating a low shear rate of 2.4 sec−1 to 7sec−1 (24-70 rpm) and a high speed disperser delivering a shear raterange of 115-345 sec−1 (1150-3450 rpm); Turello mixer (TurelloManufacturer: Construzioni Meccaniche, Zona Artigianale, Via Dei Ponti,Spilimbergo), a mixing and compounding device having two mixing blades,one mixing blade operating at a low shear rate of 2 sec−1 to 6 sec−1(20-60 rpm), and the other two high speed dispersers delivering a shearrate range of 30 sec−1 to 310 sec−1 (300 rpm to 3000 rpm); Hauschildmixer (Hauschild universal mixer: Hauschild mixer, model AM 501,Waterkamp 1, 59075 Hamm, Germany; supplied through Flacteck, LandrumS.C.), a rotational mixing device operating at a fixed shear rate of1032 sec−1 or 3000 rpm.

[0074] Mixing can also be accomplished in a continuous process such asan extruder. A twin screw co-rotating fully inter-meshing extruder,2-lobe, 3-lobe or greater screw elements (multi-lobe elements) with highlength to diameter (L/D) is particularly useful for the process of thepresent invention because of its flexibility in allowing multipleadditions of water at controlled quantities at selected locations andits ability to effectively disperse water quickly via dispersive andshear mixing.

[0075] When a twin screw co-rotating extruder is used for mixing in thepresent invention, sufficient mixing can be accomplished through screwconfiguration design, selection of water injection ports along theextruder, and the control of screw operating conditions. An effectivescrew configuration suitable for continuous emulsification processrequires choices of screw elements and proper configuration of suchscrew elements in such order that the completed screw configuration maycause desirable dispersion and distribution of water into the mixture.There are many commercially available screw elements which may beselected for constructing a useful screw configuration. Illustrativeexamples of such screw elements include; medium/wide discs kneadingblocks for dispersive shearing mixing, screw mixing elements and turbinemixing elements for mixing action, and screw bushings for conveyingpurposes. There are many variations among each type of screw elements.For example, there are wide discs, medium discs, thin discs, and discsin neutral, right handed and left handed directions for the kneadingblocks type alone, and 2-lobe or 3-lobe screw elements. For thoseskilled in the art, it should be obvious that by properly combiningdifferent type of screw elements and in certain orders one can devisescrew configurations to perform desirable shear and mixing means atspecific segments of the extruder. One skilled in the art can furtherdevelop a process where low viscosity surfactants and water may beincorporated into the silylated elastomeric polymer at selectedinjection ports along the extruder where the water and surfactants maybe effectively dispersed prior to the next water injection, to providethe preferred amounts and rates of water addition in accordance with thepresent invention.

[0076] The premix embodiment of the process for preparing awater-continuous emulsion of a silylated elastomeric polymer of thepresent invention comprises the steps of:

[0077] (I) Forming a Premix Comprising;

[0078] (A) 100 parts of a silylated elastomeric polymer having aviscosity of 0.5 to 1,000,000 KPa-s and a glass transition temperatureup to 50° C.,

[0079] (B) 3 to 30 parts of a surfactant,

[0080] (II) Adding

[0081] (C) 5 to 45 parts water to the premix with mixing

[0082] thereby forming a water-continuous emulsion of the silylatedelastomeric polymer having a solids content of greater than 75%, anaverage particle size less than 5 μm, and has sufficient stability toproduce a stable lower solids emulsion upon dilution with water.

[0083] Optional components (D) and (E), as described infra, can be addedto the premix.

[0084] The formation of the premix in step (I) comprising the silylatedelastomeric polymer (A), surfactant (B), and optionally, plasticizer (D)and low molecular weight acid (E) can be accomplished by any of themixing methods described infra. The temperature and pressure at whichmixing occurs to effect the formation of the premix is not critical, butgenerally is conducted at ambient temperature and pressure.

[0085] The second step of the premix embodiment of the present processinvolves adding 5 to 45 parts water to the premix with mixing to form awater-continuous emulsion of the silylated elastomeric polymer having anaverage particle size less than 5 μm and having sufficient stability toproduce a stable lower solids emulsion upon dilution with water. Theamount of water added can vary from 5 to 45 parts per 100 parts byweight of the premix. The water is added to the premix at such a rate soas to form a stable high solids emulsion of the silylated elastomericpolymer. While this amount of water can vary depending on the selectionof the silylated elastomeric polymer and surfactant, generally theamount of water is from 5 to 45 parts per 100 parts by weight of thepremix, and more preferably is from 5 to 30 parts per 100 parts byweight of the premix, and most preferably is from 5 to 20 parts per 100parts by weight of the premix.

[0086] The mixing methods in step (II) of the premix embodiment can beaccomplished by the same or different mixing methods as in step (I) andcan be selected from the methods described infra. Preferably, the mixingmethods for the water addition in step (II) is the same as the mixingmethods used to form the premix in step (I). The temperature andpressure at which the water addition step (II) occurs is not critical,but preferably mixing is conducted at ambient temperature and pressures.

[0087] The process for preparing the water continuous emulsion of asilylated elastomeric polymer of the present invention also encompassesan embodiment that comprises;

[0088] adding

[0089] (B) 3 to 30 parts of a surfactant

[0090] (C) 5 to 45 parts water

[0091] and optionally

[0092] (D) a plasticizer

[0093] (E) a low molecular weight acid

[0094] to

[0095] (A) 100 parts of a silylated elastomeric polymer having aviscosity of 0.5 to 1,000,000 KPa-s and a glass transition temperatureup to 50° C., with mixing, wherein the water (C) is added in incrementalportions, whereby each incremental portion comprises less than 8 weight% of the components (A) and (B) combined and each incremental portion ofwater is added successively to the previous after the dispersion of theprevious incremental portion of water, wherein sufficient incrementalportions of water are added to form the water-continuous emulsion of thesilylated elastomeric polymer. Components (A), (B), (C), (D) and (E) arethe same as described infra. The mixing in this embodiment can beaccomplished by any of the aforementioned techniques. Likewise, thetemperature and pressure of the mixing is not critical and typicallyoccurs at ambient conditions. Preferably, this embodiment is conductedin a continuous process, and most preferably conducted on a twin screwextruder.

[0096] Other optional ingredients may be added to the water continuousemulsions of the present invention as desired to affect certainperformance properties, providing the nature and/or quantity of theseoptional ingredients does not substantially destabilize thewater-continuous emulsions of the present invention. These optionalingredients include, fillers, freeze-thaw additives such as ethyleneglycol or propylene glycol, antimicrobial preparations, UV filters,antioxidants, stabilizers, pigments, dyes, and perfumes.

[0097] The emulsions of the present invention are useful in coatingapplications requiring no or little presence of organic solvents. Inparticular, the emulsions of the present invention are useful in thosecoating applications requiring flexible film formation with improvedwater resistance or gas/vapor permeability.

EXAMPLES

[0098] The following examples are presented to further illustrate thecompositions and methods of this invention, but are not to be construedas limiting the invention, which is delineated in the appended claims.All parts and percentages in the examples are on a weight basis and allmeasurements were obtained at about 23° C., unless indicated to thecontrary.

[0099] The particle size of the emulsion was determined using a MalvernMastersizer S unit. The unit was equipped with 300 RF mm range lenscapable of detecting a particle size range from 0.05 μm to 900 μm. Thedata was analyzed using a polydisperse model and calculated per theFraunhofer model. The results from these measurements are reportedherein as;

[0100] D(v, 0.5), the size value of particle at which 50% of the sampleis smaller and 50% is larger than this value. This value is defined asthe average particle size of the emulsion sample in this invention, alsoknown as the mass median diameter.

[0101] D(v, 0.9), the size value of particle for which 90% of the sampleis below this size.

[0102] Span, the measurement of the width of the distribution. It iscalculated as the ratio of the difference between D(v, 0.9) and D(v,0.1) to D(v, 0.5). The smaller the value, the narrower the particle sizedistribution.

[0103] The “zero-shear” viscosity of silylated elastomeric polymers inthis invention were either experimentally derived or adopted fromavailable commercial literatures. To derive the zero-shear viscosity ofa silylated elastomeric polymer, the apparent viscosity of the elastomerat different shear rates (1/sec) or angular frequencies (rad/sec) weremeasured on a shear stress rheometer at 25° C. A CSL 500 Rheometer fromTA Instruments Inc., (New Castel, Del.) (also known under Cari-MedRheometer) was used to carry out the measurements. A variety of samplegeometries were used to in order to carry out the viscositymeasurements. For high viscosity polymers, cone and plate and parallelplate at selected diameters were used. For example, the 2 cm diametercone and plates were used for very high viscosity polymers and the 6 cmdiameter cone and plates for moderately low viscosity polymers. The coneand plate was used for homogeneous materials and emulsions withsub-micrometer (μm) particles, and parallel plate geometry was used forparticulate containing or multi-component mixtures. Additionally, thecone and plate geometry was used for highly shear rate sensitivematerials.

[0104] When an extruder was used for mixing and forming the emulsions, amodular 25 mm co-rotating, fully intermeshing twin-screw extrudermanufactured by Krupp Werner & Pfleiderer Corporation (Ramsey, N.J.) wasused. The extruder was powered by a 21.5 KW AC motor with a Flux VectorDrive capable of generating screw speeds of up to 1200 rpm. The diameterof each screw was 25 mm and the channel depth was 4.15 mm. The freespace cross sectional area was 3.2 cm². The overall length to diameterratio L/D of the machine was 56:1. The extruder module had 14 barrelswith one injection port on each barrel. The polymer was fed to theextruder via a single screw Bonnot Extruder and the screw was tapered toensure accurate flow control and delivery. Additives, surfactants, acid,and water were delivered to the extruder via precision pumps and flowcontrol valves to selected ports on the extruder.

Example 1

[0105] Four high solids water-continuous emulsions of various silylatedcopolymers of isobutylene and methyl styrene (Si PIB) polymers wereprepared. The Mn, Mw, % Si, and viscosities of these four silylated PIBpolymers are summarized in Table 1. These silylated PIB polymers wereprepared according to the procedures detailed in U.S. Pat. No.6,177,519.

[0106] The following general procedure was used for Runs 1-4. Thecompositions and resulting emulsion properties for Runs 1-4 aresummarized in Table 1.

[0107] A 1 gallon Ross mixer equipped with double planetary mixer bladeswas charged with 2500 g of a dimethoxymethylsilyl-functionalpoly(isobutylene-co-paramethylstyrene) and heated at 50° C. for 2 hours.Then, 375 g of a hydrocarbon oil, Daphne KP-100 (formula weight 490g/mole, Apollo America Corp.) was added with at an agitation speed ofabout 15-25 rpm (about a shear rate of 1.5 to 2.5 sec−1) and mixed for 2hours to produce a homogeneous mixture. To this mixture was added amixture of 80 g of Brij 30, 120 g of Brij 35L (@72% solids), 120 g ofBrij 97, (ICI Surfactants, Uniqema, Wilmington, Del.) and 7.5 g ofacetic acid at a mixing speed of 15-25 rpm until a homogeneouspolymer/surfactants mixture (premix) was obtained (typically after anadditional 2 hours of mixing).

[0108] The prepared polymer/surfactants mixture (premix) was transferredto a 10 liter Turello mixer. No heat was applied. The agitator/scraperwas started at about 30 rpm and the high speed disperser was started atabout 500 rpm (about 50 sec−1 shear rate). An initial 50 g of de-ionizedwater was gradually added to the mixture while mixing. This amount ofwater corresponded to about 1.5 wt. % of the polymer/surfactants mixture(premix). Next, 50 g of de-ionized water was incorporated only after theprevious water was fully incorporated, that is there were no visiblewater droplets in the mixture. The high speed disperser was adjustedbetween 1000 rpm (about 105 sec−1 shear rate) to near 2800 rpm (about295 sec−1 shear rate) to ensure a effective and homogeneous dispersion.A total of 525 g water was incorporated in 50 g increments, with thelast increment being 25 g, to produce a water-continuous emulsion, asevidenced by its miscibility with water.

[0109] All four runs produced water-continuous emulsions havingexcellent shelf and aging stability. All the emulsions exhibited nosignificant change after 4 months of aging, rather they remained smooth,creamy and water-dilutable. The particle size measurements for the 4month aged samples are also summarized in Table 1. TABLE 1 Run 1 2 3 4SiPIB polymer property % pMS in SiPIB 5 8 5 8 Polymer viscosity, poise1,500,000 1,800,000 615,000 1,800,000 Si % 1.17 2.35 1.53 2.35 Mw,g/mole 63,790 76,600 44770 76,600 Mn, g/mole 31,870 30,640 26820 30,640Si-grafted PIB polymer 2500 2500 2500 2500 KP-100 375 375 375 250Isotearic acid (Emersol 873) 250 Brij 30 80 80 80 Brij 35L (@ 72%solids) 120 120 120 250 Brij 97 120 120 120 125 Acetic acid 7.5 7.5 7.57.5 Water, de-ionized 525.0 515.0 515.0 825.0 % Solids (actual) 85.786.0 86.0 80.0 Particle size profile Malvern, initial D(v, 0.5),micrometers 0.63 0.6 0.57 0.56 D(v, 0.9), micrometers 1.58 1.32 1.671.66 Span 2.14 1.80 2.63 2.64 Malvern, 4-month aging D(v, 0.5),micrometers 0.608 0.558 0.572 0.515 D(v, 0.9), micrometers 1.49 1.221.63 1.5 Span 2.1 1.8 2.52 2.55

Example 2

[0110] Five high solids emulsions were made in a lab-scale Hauschildmixer using the following general procedure. In these runs, the samepolymer and surfactants were used, but the amount of water added inincremental portions was varied. The polymeric elastomer was adimethoxymethylsilyl-functional poly(isobutylene-co-paramethylstyrene),prepared according to the procedures detailed in U.S. Pat. No.6,177,519. The polymer had a viscosity 180,000 Pa.s (1,800,000 poise),2.35% Si content, 8% paramethylstyrene units in the copolymer, and Mw of76,600 g/mole, and Mn of 30,640 g/mole.

[0111] First, 40.0 g of the dimethoxymethylsilyl-functionalpoly(isobutylene-co-paramethylstyrene) was weighed into a clean plasticcontainer. The material was pre-heated to 50° C. for about 2 hours. Then6.0 g of a petroleum hydrocarbon oil, Daphne KP-100 (formula weight of490 g/mole, Apollo America Corp.) was added to the polymer. The mixturewas spun in Hauschild mixer to homogeneous, typically 100 seconds at arevolving/rotating motion at a speed of 3000 rpm (or shear rate of 1150sec−1). Then the following surfactants and acid were incorporated intothe polymer mixture: 0.8 g of Brij 30 (POE (4) Lauryl ether, HLB 9.5,Uniqema), 1.20 g of Brij 97 (POE(10) Oleyl ether, HLB 12.4, Uniqema),and 1.70 g of Brij 35L (72% solids, POE(23) Lauryl ether, HLB 16,9,Uniqema), and 0.12 g of acetic acid. The mixture was spun in Hauschildmixer for additional 75 seconds to homogeneous.

[0112] In Run #5, 0.5 g of de-ionized water per addition was used. Thiswas about 1.0 wt. % of the polymer/surfactants solids. The water wasspun for at 60 seconds at the fixed speed of about 3000 rpm (or a shearrate of about 1150 sec−1) to thoroughly disperse the water. The nextaddition of 0.5 g water was incorporated, and spun mixed to uniformstate. It was observed that a smooth, creamy, water-continuous emulsionwas obtained only after 4.8 wt. % water was incorporated. Thiswater-continuous emulsion had a high solids content of 95.2% by weight.The emulsion had an average particle size D(v, 0.5) of 0.479micrometers, D(v,0.9) of 1.37 micrometers and a span of 2.48. Additionalwater was added to dilute the emulsion to about 85 wt. % solids. Thefinal emulsion has an average particle size D(v,0.5) of 0.463micrometers, D(v,0.9) of 1.40 micrometers, and a span of 2.62.

[0113] Runs 6-9 varied the amount of water used in each addition, from1.0 g per addition (equivalence of 2.0 wt. % per polymer/surfactants) inrun #6 to 8 g per addition (equivalence of 16.0 wt. % perpolymer/surfactants) in Run #9. As summarized in the Table 2, Run #9produced an emulsion having large and broad particle size and a bi-modalprofile. This emulsion had less than 4 weeks stability in storage. Theemulsion produced in Run #8 had good average particle size, but withlarge particles up to 10 micrometers size. This emulsion alsodeteriorated over time.

[0114] These results demonstrate the rate of water addition as having animpact on the quality and stability of emulsion. TABLE 2 Run # 5 6 7 8 9Wt. % water per 1.0% 2.0% 4.0% 8.0% 16.0% addition Amount water per 0.5g/addition 1 g/addition 2 g/addition 4 g/addition 8 g/addition additionWt. % solids at 95.2 95.2 95.2 91.7 85.4 inversion point* Emulsion 0.479μm; 0.494 μm; 0.551 μm; 0.604 μm; 0.743 μm; particle profile at 1.37 μm;1.34 μm; 1.46 μm; 1.69 μm; 5.12 μm; inversion point 2.48 2.33 2.29 2.456.61 (bi-modal) Final emulsion at 0.463 μm; 0.506 μm; 0.544 μm; 0.615μm; 0.743 μm; 85% solids 1.40 μm; 1.35 μm; 1.56 μm; 1.67 μm; 5.12 μm;2.62 2.28 2.52 2.38 (to 10 μm) 6.61 (bi-modal)

Example 3

[0115] Runs 10-13 were conducted using various alkylphenol ethoxylatestype surfactants to prepare these emulsions. Triton X-100, an POE (9)octylphenol ether or Otoxynol-9 (HLB of 13.5, Union Carbide, DowChemical, Midland, Mich.) and Triton X-305, an POE (30) octylphenolether or Octoxynol-30 (HLB of 17.3, Union Carbide, Dow Chemical,Midland, Mich.) were used in different ratio, while the totalsurfactants in solids remained constant, thus resulted in a surfactantpackage with different HLB values. The polymer was the samedimethoxymethylsilyl-functional poly(isobutylene-co-paramethylstyrene),used Runs 5-9; as was the general procedure.

[0116] Water at 1.0 g per addition (equivalence of 2.0 wt. % perpolymer/surfactants) was incorporated until the point of the formationof a water-continuous, creamy emulsion. The particle size profile at thepoint of first inversion, and the particle size profile for the 85 wt. %solids emulsion are shown in Table 3. TABLE 3 Run # 10 11 12 13 Wateraddition rate 2.0% 2.0% 2.0% 2.0% Surfactants Triton X-100 4.6 3.0 2.40.0 Triton X-305 (70% solids) 0.0 2.3 3.1 6.5 acetic acid 0.12 0.12 0.120.12 HLB value 13.5 14.8 15.2 17.2 Wt. % solids at 91.5 93.2 93.2 93.2inversion Emulsion particle 0.65 μm; 0.66 μm; 0.69 μm; 0.71 μm; profileat inversion 4.94 μm; 4.66 μm; 7.37 μm; 3.18 μm; point 7.33 (tail to 100μm) 6.75 (tail to 30 μm) 10.40 (tail to 60 μm) 4.16 Final emulsionparticle 0.59 μm; 0.61 μm; 0.66 μm; 0.65 μm; profile at 85% solids 3.02μm; 1.91 μm; 2.10 μm; 2.20 μm; 4.85 (tail to 60 μm) 2.81 2.86 3.08

Example 4

[0117] This example shows a high solids emulsion of a silane-grafted PIBpolymer can be prepared in a 1 quart Ross low shear mixer equipped witha set of high viscosity (HV) blades fitted to a double planetary mixingaction.

[0118] The silylated elastomeric polymer used in this example was adimethoxymethylsilyl-grafted poly(isobutylene-co-paramethylstyrene) wasprepared according according to the procedures detailed in U.S. Pat. No.6,177,519 and characterized to have 1.61% Si, Mw of 66,580 g/mole and Mnof 29,210 g/mole and a viscosity of about 160,000 Pa-s (1.6 MM Poise).

[0119] A 1-quart Ross mixing vessel was charged with 672 g of thesilane-grafted poly(isobutylene-co-paramethylstyrene). The polymer washeated to and held at 50° C. for 2 hours, then 128 g of a petroleumhydrocarbon oil, Daphne KP-100 (490g/mole m.w.; Apollo America Corp.)was added and mixed to form a homogeneous mixture with a set of highviscosity blades turning at about 15 rpm speed. This yielded a sheardispersion action at a shear rate of about 1.5 sec−1. The heat wasturned off to allow the mixture returned to ambient temperature. Asurfactant mixture consisting of 32 g of Brij 30, 64 g of Brij 35L (@72%solids), 32g of Brij 97, and 2.8 g of acetic acid was charged to thepolymer mixture. The shear dispersion mixing resumed at about 15-20 rpmfor two more hours. A homogeneous mixture of polymer/surfactants wasobtained under this very low shear rate of 1.5 to 2.0 sec−1.

[0120] To carry out the emulsification, a small amount of de-ionizedwater was charged while the above polymer/surfactants mixture understeady shear mixing. The process began by adding 12 g of de-ionizedwater (equivalent of 1 to 1.5 wt. % per polymer/surfactants mixture) wasincorporated into the above polymer/surfactants mixture while under asteady shear dispersing mixing with the HV blades turning at about 20rpm (or a shear rate of 2 sec−1). The mixing continued until the waterwas fully incorporated into the mixture, typically about 10-15 minutes.A next water addition of 12-18 g quantity (approximate 1 to 2 wt. % ofpolymer/surfactants mixture) was introduced while the shear mixingaction continued. No subsequent water addition was allowed until theprevious water was fully incorporated. This gradual incorporation ofwater in small intervals continued while the mixture is under efficientshear dispersion mixing. When a total of about 46 g de-ionized water wassuccessfully incorporated, a water-dilutable, emulsion was formed. Thiswater-dilutable, smooth and creamy emulsion has a solids content of 93.5wt. %. This high solids emulsion has an average particle size of 0.753micrometers (D(v, 0.5)), 1.93 micrometers at 90 percentile (D(v, 0.9)),and a span of 2.23.

[0121] An additional 80 g of de-ionized water was incorporated into thejust produced emulsion to give a uniform emulsion with a solids contentof about 86%. This was done using a regular mixing/stirring device. Theemulsion has the following emulsion particle size profile: D(v, 0.5) of0.779 micrometers, D(v, 0.9) of 1.95 micrometers, and a span of 2.15.

Example 5

[0122] The silylated elastomeric polymer used in the following examplewas a dimethoxymethylsilyl-graftedpoly(isobutylene-co-paramethylstyrene), prepared according to theprocedures detailed in U.S. Pat. No. 6,177,519 and characterized to have1.61% Si, Mw of 66,580 g/mole and Mn of 29,210 g/mole and a viscosity of160,000 Pa-s (1.6 MM Poise).

[0123] A 1-quart Ross mixing vessel was charged with 650 g of asilane-grafted poly(isobutylene-co-paramethylstyrene). The polymer washeated to and held at 50° C. for about 2 hours. A surfactant mixtureconsisting of 71 g of Brij 35L (@72% solids), 40g of Brij 97, and 2.0 gof acetic acid was charged to the polymer mixture. The shear dispersionmixing resumed at about 15 rpm (equivalent shear rate of 1.5 sec−1) forone hour, then raised mixing speed to 130 rpm (about 13 sec−1). Ahomogeneous mixture of polymer/surfactants was obtained. Water wasgradually added to the polymer/surfactant mixture at a rate of 2 g every5 minutes, and repeated until a total of 45 g water was added and awater-continuous, creamy emulsion was observed. After this point,additional 105 g dilution water was incorporated and mixed tohomogeneous. The emulsion was measured to have sub-micron particle sizeand profile.

Example 6

[0124] Two commercial samples of a dimethoxymethylsilyl-terminatedpolypropyleneoxide polyether, MS203H having a viscosity of 16 Pa-s andMS303H having a viscosity of 26 Pa-s, both from Kaneka Corporation wereused to prepare mixtures of silylated elastomeric polymers foremulsification. These dimethoxymethylsilyl-terminated polypropyleneoxidepolyethers were mixed with two types of dimethoxysilyl-functionalelastomers: a dimethoxylsilyl-functionalpoly(isobutylene-co-para-methylstyrene) copolymer prepared according tothe procedures detailed in U.S. Pat. No. 6,177,519 and having aviscosity of 0.15 MM KPa.s (1.5 MM poise); and Epion 300S adimethylsilyl-terminated polyisobutylene (Si-PIB) having anumber-average molecular weight of 10,000 g/mole, and a viscosity of 1.6KPa-s, obtained commercially from Kaneka Corporation.

[0125] As shown in Table 4, emulsions of silane-functional curableelastomeric emulsions consisting of silane-graftedpoly(isobutylene-co-p-methylstyrene) and silyl-functional polyether weresuccessfully prepared. A water-continuous and water-dilutable emulsionat as high as 94 wt. % solids was formed and was dilutable to a weight %solids of 75.0 or higher. TABLE 4 SiPIB polymer batch type Si-(PIB-pMS)Epion 300S Polymer batch Kaneka MS S303H Kaneka MS S203H SiPIB polymer20.0 g 20.0 g Polyether polymer 20.0 g 20.0 g Brij 35L (72% solids) 3.0g 3.0 g Brij 97 1.4 g 1.4 g Acetic acid 0.12 g 0.12 g Water, toformation (0.5 g 4.8 g 2.0 g each addition) D.I. Water, dilution 9.4 g7.3 g Wt. % solids at formation 90.0 94.0 Wt. % solids, final 75.0 81.1PH @ 25 C 7.249 7.25 Particle size profile, initial D(v, 0.5),micrometers 0.417 0.47 D(v, 0.9), micrometers 1.71 1.04 Span 3.83 1.9

Example 7

[0126] Silane-grafted poly(isobutylene-co-p-methylstyrene), preparedaccording to the procedures detailed in U.S. Pat. No. 6,177,519, waspumped, via a gear pump, into a 25 mm twin-screw extruder, the mixtureconsisting of Brij 35L, Brij 97, and acetic acid was incorporated via aprecision metering pump into the extruder and was shear mixed to form ahomogeneous polymer premix. To effect the emulsification, multiple wateradditions, each at a prescribed weight % of the polymer premix, weregradually incorporated into the twin-screw extruder via precisionmetering pumps. To produce emulsions of desirable particle size profile,the initial water additions were kept at 1.2 to 2.0 wt. % of the polymerpremix, and the water was fully dispersed and incorporated into thepolymer premix prior to subsequent water addition.

[0127] As shown in Table 5, emulsions up to about 94 weight % solids andaveraged particle size of about 0.5 micrometers were produced, and aslittle as 6 weight % of water was needed to produce high qualityemulsion of plasticizer-free curable silylated elastomeric polymers. Thewater was introduced via injection ports from 1 through 5. TABLE 5 Run #14 15 16 17 18 19 20 21 22 SiPIB polymer, g/min 179 179 179 179 179 179179 179 179 Acetic acid, g/min 0.78 0.78 0.78 0.78 0.78 0.78 0.78 0.780.78 Brij 35L (72%), g/min 20.5 20.5 20.5 20.5 20.5 20.5 20.5 20.5 20.5Brij 97, g/min 9.7 9.7 9.7 9.7 9.7 9.7 9.7 9.7 9.7 water 1, g/min 4.04.0 4.0 4.0 4.0 4.0 4.0 2.4 2.4 water 2, g/min 4.0 4.0 4.0 4.0 4.0 4.04.0 2.4 2.4 water 3, g/min 12.5 15.0 15.0 12.5 15.0 12.5 12.5 12.5 water4, g/min 12.5 15.0 15.0 12.5 15.0 12.5 12.5 12.5 water 5, g/min 20.030.0 25.0 0.0 25.0 Total water added, g/min 13.7 38.7 43.7 43.7 58.773.7 63.7 35.5 60.5 total amount produced, g/min 218.0 243.0 248.0 248.0263.0 278.0 268.0 239.8 264.8 Water 1 rate, wt. %/premix 2.0 2.0 2.0 2.02.0 2.0 2.0 1.2 1.2 Water 2 rate, wt. %/premix 2.0 2.0 2.0 2.0 2.0 2.02.0 1.2 1.2 Water 3 rate, wt. %/premix 6.1 7.3 7.3 6.1 7.3 6.1 6.1 6.1Water 4 rate, wt. %/premix 6.1 7.3 7.3 6.1 7.3 6.1 6.1 6.1 Water 5 rate,wt. %/premix 9.8 14.7 12.2 0.0 12.2 Screw speed, rpm 300 300 300 400 400400 400 800 1200 Average shear rate, sec-1 94.2 94.2 94.2 125.6 125.6125.6 125.6 251.2 376.8 Wt. % solids 93.7 84.1 82.4 82.4 77.7 73.5 76.285.2 77.1 Particle size, initial D(v, 0.5), micrometers 0.533 0.6470.624 0.573 0.64 0.669 0.629 0.665 0.673 D(v, 0.9), micrometers 1.691.77 1.7 1.64 1.63 1.65 1.64 1.79 1.77 Span 2.92 2.48 2.47 2.61 2.262.18 2.34 2.42 2.36

Example 8

[0128] Two emulsions containing selected organic plasticizers wereprepared. The compositions and the emulsion properties are shown inTable 6. They were prepared by incorporating the respective plasticizersinto the silane-grafted poly(isobutylene-co-p-methylstyrene), preparedaccording to the procedures detailed in U.S. Pat. No. 6,177,519,followed by dispersing the Brij 97 and Brij 35L surfactants and aceticacid into the plasticized polymer mixture. To the homogeneous polymerpremix, water at 0.5 to 1.0g quantity at each addition, was added andshear dispersed and mixed into the polymer premix, followed by a highshear mixing in a bench-top Hauschild universal mixer to fully dispersethe water into the premix. Multiple water additions were made till asmooth creamy emulsion was formed. The emulsions had 85+% by weightsolids and sub-micron particle size. They are stable at storage andreadily dilutable in water to lower solids levels. TABLE 6 SiPIB polymer40.0 g 40.0 g KP-100 hydrocarbon oil 8.0 g DIOA (diisooctyl adipate)ester 12.0 g Brij 97 2.0 g 2.1 g Brij 35L (72% solids) 4.0 g 4.1 gAcetic acid 0.12 g 0.12 g Water 10.3 g 14.5 g Final emulsion smooth,creamy smooth, creamy Wt. % solids 87.2 86.2 Particle size profile D(v,0.5), micrometers 0.64 0.343 D((v,0.9), micrometers 1.59 0.57 Span 2.061.03

Example 9

[0129] An emulsion of poly(isobutylene-co-p-methylstyrene) grafted withmethylvinyldimethoxysilane (same as Example 7) was prepared using a 25mm twin screw extruder. The selected silane-graftedpoly(isobutylene-co-p-methylstyrene) (Si—P(IB-co-pMS)) was incorporatedwith a selected amount of surfactants, acetic acid, and a first wateraddition (water 1), per the formulation, addition rates and additionpoints summarized in Table 7, to form the high solids emulsion. Theemulsion inverts ca. 12 L/D after the first water addition. The finalsolid content was selected by adding water (water 2) at a prescribedweight % at the end of the extruder. The emulsion properties aresummarized in Table 7. TABLE 7 Addition point* Si-P(IB-co-pMS) polymer,g/min 243.8 Acetic acid, g/min 5.2 0.68 Brij 35L (72%), g/min 5.2 20.5Brij 97, g/min 5.2 9.7 water 1 g/min 5.2 12.8 water 2, g/min 36 28.1Total amount, g/min 315.6 Water rate 1, wt. %/premix 4.7 Water rate 2,wt. %/premix 10.3 Screw speed, rpm 200 Wt. % solids 87.0 particle sizeprofile D(v,0.5), micrometers 0.591 D(v,0.9), micrometers 1.42 Span 2.11D[4,3] 0.71

We claim:
 1. A water-continuous emulsion composition comprising; (A) 100parts of a silylated elastomeric polymer having a viscosity of0.5-1,000,000 KPa-s and a glass transition temperature up to 50° C., (B)3 to 30 parts surfactant (C) 5 to 45 parts water wherein thewater-continuous emulsion has a solids content of greater than 75%, anaverage particle size less than 5 μm, having sufficient stability toproduce a stable lower solids emulsion upon dilution with water.
 2. Thewater-continuous emulsion composition of claim 1 wherein the silylatedelastomeric polymer is a silylated polymer derived from elastomericpolymers selected from natural rubber, styrene-butadiene, butadiene,ethylene-propylene-diene (EPDM), butyl rubber, nitrile rubber,chloroprene rubber, fluorocarbon elastomers, polysulfide rubbers, andpolyurethane.
 3. The water-continuous emulsion composition of claim 1wherein the silylated elastomeric polymer is a curable silylatedelastomeric polymer.
 4. The water-continuous emulsion composition ofclaim 1 wherein the silylated elastomeric polymer is a silylatedpolyisobutylene polymer in which at least 50 mole percent of the repeatunits are isobutylene units.
 5. The water-continuous emulsioncomposition of claim 1 wherein the silylated elastomeric polymer is asilylated copolymer of an isomonoolefin and a vinyl aromatic monomer. 6.The water-continuous emulsion composition of claim 5 wherein thesilylated copolymer is the reaction product of a) an olefin copolymercomprising at least 50 mole % of at least one C₄ to C₇ isomonoolefin andat least one vinyl aromatic monomer; b) a silane of the general formulaRR′SiY₂ wherein R represents a monovalent olefinically unsaturatedhydrocarbon or hydrocarbonoxy radical, each Y represents a hydrolyzableorganic radical and R′ represents an alkyl radical, an aryl radical or aY radical; and c) a free radical generating agent.
 7. Thewater-continuous emulsion composition of claim 5 wherein the silylatedcopolymer comprises at least 60 mole % of at least one C₄ to C₇isomonoolefin.
 8. The water-continuous emulsion composition of claim 5wherein said vinyl aromatic monomer is an alkylstyrene and said alkylstyrene comprises para-methylstyrene.
 9. The water-continuous emulsioncomposition of claim 8 wherein the silylated copolymer comprises atleast 80 mole % of isobutylene and from 0.1 up to 20 mole % ofpara-alkylstyrene.
 10. The water-continuous emulsion composition ofclaim 1 further comprising; (D) a plasticizer.
 11. The water-continuousemulsion composition of claim 10 wherein (D) the plasticizer is asaturated or unsaturated hydrocarbon containing at least 8 carbon atoms.12. The water-continuous emulsion composition of claim 9 wherein (D) theplasticizer is selected from mineral oil, carboxylic acid functionalhydrocarbons containing at least 8 carbon atoms, and ester functionalhydrocarbon containing at least 8 carbon atoms.
 13. The water-continuousemulsion composition of claim 1 wherein the surfactant is apolyoxyalkylene alkyl ether.
 14. The water-continuous emulsioncomposition of claim 1 wherein the surfactant is a reaction productbetween a carboxylic acid functional hydrocarbon and an amine functionalhydrocarbon.
 15. The water-continuous emulsion composition of claim 14wherein the carboxylic acid functional hydrocarbon is selected from afatty acid and the amine functional hydrocarbon is selected from ahydrophilic amine.
 16. The water-continuous emulsion composition ofclaim 15 wherein the fatty acid is isostearic acid and the hydrophilicamine is a secondary amine alcohol.
 17. The water-continuous emulsioncomposition of claim 1 further comprising (E), a low molecular weightacid.
 18. The water-continuous emulsion composition of claim 10 furthercomprising (E), a low molecular weight acid.
 19. The water-continuousemulsion composition of claim 17 wherein the low molecular weight acidis acetic acid.
 20. The water-continuous emulsion composition of claim18 wherein the low molecular weight acid is acetic acid.
 21. Thewater-continuous emulsion composition of claim 18 wherein the silylatedelastomeric polymer is a silylated copolymer of an isomonoolefin and avinyl aromatic monomer, the surfactant is a polyoxyalkylene alkyl ether,and the plasticizer is mineral oil.
 22. A process for preparing awater-continuous emulsion of a silylated elastomeric polymer comprisingthe steps of: (I) Mixing; (A) 100 parts of a silylated elastomericpolymer having a viscosity of 0.5 to 1,000,000 KPa-s and a glasstransition temperature up to 50° C., (B) 3 to 30 parts of a surfactant,(C) 5 to 45 parts water, to form a water-continuous emulsion of thesilylated elastomeric polymer having a solids content of greater than75%, an average particle size less than 5 μm, and has sufficientstability to produce a stable lower solids emulsion upon dilution withwater.
 23. The process of claim 22 wherein the water is added inincremental portions, whereby each incremental portion comprises lessthan 8 weight % and each incremental portion of water is addedsuccessively to the previous after the dispersion of the previousincremental portion of water, wherein sufficient incremental portions ofwater are added to form the water-continuous emulsion of the elastomericpolymer.
 24. The process of claim 22 wherein each successive incrementalportion of water comprises less than 4 weight % of components (A) and(B) combined.
 25. The process of claim 22 wherein the successiveincremental portion of water comprises less than 2 weight % ofcomponents (A) and (B) combined.
 26. The process of claim 22 wherein thesilylated elastomeric polymer is a polyisobutylene polymer in which atleast 50 mole percent of the repeat units are isobutylene units.
 27. Theprocess of claim 22 wherein the elastomeric polymer is a silylatedcopolymer of an isomonoolefin and a vinyl aromatic monomer.
 28. Theprocess according to claim 22 wherein (D), a plasticizer, is included inthe mixing.
 29. The process of claim 28 wherein (D) the plasticizer isselected from mineral oil, isostearic acid, and diisooctyl adipate. 30.The process of claim 22 wherein (E), a low molecular weight acid, isincluded in the mixing.
 31. The process of claim 28 wherein (E), a lowmolecular weight acid, is included in the mixing.
 32. The process ofclaim 30 wherein the low molecular weight acid is acetic acid.
 33. Theprocess of claim 22 wherein 5 to 30 parts of water are added.
 34. Theprocess of claim 33 wherein 5 to 20 parts of water are added.
 35. Theprocess of claim 22 further comprising the step of; (II) mixingadditional water to the water-continuous emulsion of the silylatedelastomer polymer to form a diluted emulsion of the silylated elastomerpolymer.
 36. The process of claim 22 wherein the mixing is provided by acontinuous mixer.
 37. The process of claim 36 wherein the continuousmixer is an extruder.
 38. The process of claim 22 wherein the mixing isprovided by a batch mixer.
 39. The water-continuous emulsion produced bythe process of claim
 22. 40. The water-continuous emulsion produced bythe process of claim
 23. 41. The water-continuous emulsion produced bythe process of claim
 28. 42. The water-continuous emulsion produced bythe process of claim
 30. 43. The water-continuous emulsion produced bythe process of claim
 35. 44. The water-continuous emulsion produced bythe process of claim 37.